Syringes are generally utilized to inject medications and other fluids into the bloodstream of patients. Syringes are also used to aspirate or withdraw various fluids, such as blood, from patients.
When a syringe is used, the contact of the syringe needle with the patient can lead to contamination of the syringe, including the needle, with various contagious micro-organisms. The contaminated syringe and needle then pose a risk to anyone handling the syringe if the person accidentally pricks or contacts themselves or someone else with the contaminated needle.
The danger of infection from contaminated needles and syringes has become of increased concern with the discovery of HIV (human immunodeficiency virus) which causes AIDS (Acquired Immune Deficiency Syndrome). The danger also exists for other infectious diseases and infections, such as hepatitis, streptococcal sepsis, tetanus, tuberculosis, Rocky Mountain Spotted Fever, and malaria.
The problem is especially relevant in the health care industry. Each year, 7% of hospital employees are involved in needle stick injuries, of which 60% are nurses. It is estimated that 57% of accidental needle sticks occur while attempting to recap the needle of a syringe or in disposal of the syringe. It is also estimated that in excess of $28.3 million is spent annually in the United States for the diagnosis and initial treatment of needle sticks.
Various strategies to deal with this problem have been attempted. One approach involves the use of some sort of cap to cover the syringe needle after use, to prevent contact with the needle. This cap can be as simple as the original plastic cap which is used to cover the needle prior to use. However, the motion required to replace the original needle cap allows for error resulting in needle contact. This is due to the relatively small diameter of the cap and the required movement of a hand toward the contaminated needle during cap replacement.
Other approaches provide for additional means for covering the needle, in the form of shields. A highly effective example of a shield is disclosed in U.S. Pat. No. 5,290,255 to Vallelunga et al., entitled APPARATUS FOR SHIELDING A SYRINGE NEEDLE, issued Mar. 1, 1994 and incorporated herein by reference.
The needle shield disclosed in the above-referenced U.S. patent to Vallelunga et al. provides a means for preventing pricks and contact with contaminated needles, without interfering with the normal usage of a syringe. The needle shield is easily manufactured in conjunction with a syringe and/or may be easily assembled onto an existing syringe if manufactured separately.
Other examples of needle shield systems are disclosed in U.S. Pat. No. 4,666,435 (Braginetz, May 1987), U.S. Pat. No. 4,871,355 (Kikkawa, October 1989), U.S. Pat. No. 4,923,447 (Morgan, May 1990),U.S. Pat. No. 5,024,616 (Ogle, II, June 1991), and U.S. Pat. No. 5,059,185 (Ryan, October 1991), each incorporated herein by reference.
Syringe shielding systems generally enclose the body of the syringe within a clear plastic sheath designed to be longitudinally displaced over the syringe needle after use, thereby preventing multiple uses of the needle. During normal usage of the syringe, the sheath encloses a substantial portion of the main body of the syringe, potentially reducing the readability of the underlying dosage indicia. As should be readily apparent, the inability to accurately view the dosage indicia on a syringe may pose serious health threats to a patient if an incorrect dosage of a medication is administered. This problem is especially relevant to those patients, such as diabetics, who are required to accurately self-administer injections.